Rail infrastructure owners are motivated to replace the time consuming and subjective process of manual crosstie (track) inspection with objective and automated processes. The intent is to improve rail safety in a climate of increasing annual rail traffic volumes and increasing regulatory reporting requirements. Objective, repeatable, and accurate track inventory and condition assessment also provide owners with the innovative capability of implementing comprehensive asset management systems which include owner/region/environment specific track component deterioration models. Such rail specific asset management systems would yield significant economic benefits in the operation, maintenance and capital planning of rail networks.
A primary goal of such automated systems is the non-destructive high-speed assessment of railway track infrastructure. Track inspection and assessment systems currently exist including, for example, Georgetown Rail (GREX) Aurora 3D surface profile system and Ensco Rail 2D video automated track inspection systems. Such systems typically use coherent light emitting technology, such as laser radiation, to illuminate regions of the railway track bed during assessment operations.
An important factor limiting the speed at which railway inspections and assessments can be accomplished is the performance of the measurement hardware being used to scan the railway. For example, SICK IVP Industrial Sensors of Sweden produces one of the highest speed three dimensional sensors available, capable of producing railway track measurements every 6 millimeters at 100 kilometers per hour (4600 profiles per second). Although the nominal longitudinal sample spacing resolution using a single sensor is acceptable, higher performance systems would be beneficial, increasing analysis capabilities and resulting in improved condition assessments.
What is needed, therefore, is a means to increase the survey speed of shorter longitudinal sample interval railway track inspections and assessments using sensors with limited measurement speed performance.